1. Field of the Invention
The present invention relates to a probe cover of a tympanic thermometer and a tympanic thermometer assembly, and more particularly, to a probe cover that prevents the probe of a tympanic thermometer from direct contact with external ear canal.
2. Background of the Invention
The tympanic membrane is generally considered by the medical community to be superior to oral, rectal, or underarm sites in representing the human body""s core temperature. The temperature of the tympanic membrane can be measured by detecting the infrared radiation from the tympanic membrane in the ear canal. Additionally, since the time needed for measuring the body temperature by using an infrared thermometer is only about 1 to 2 seconds, the use of infrared thermometers has become more and more prevalent, and hospitals, clinics and families use tympanic thermometer to replace a mercury thermometer.
To measure the infrared radiation in the external ear canal, the probe of a tympanic thermometer must be inserted into the external ear canal for precisely sensing the infrared radiation emitted from the tympanic membrane for determining the temperature of the tympanic membrane. However, infection and contamination may be caused due to the direct contact of the probe with the ear canal when such a tympanic thermometer is used to determine the body temperature. That is, the probe will be contaminated by the blood of different patients"" ear canals, and then the blood will be brought to contact another patient""s ear canal during subsequent measurement, and infection occurs. In order to prevent this disadvantage, a probe cover that is discarded after use generally covers the tympanic thermometer and a new one is used for each patient.
FIG. 1 shows a probe cover 10 disclosed in U.S. Pat. No. 5,163,418. The probe cover 10 includes a sheath 11 and a ring-shaped base 12. The sheath 11 is formed by infrared transparent thin film having a thickness of about 0.001 inch, and its shape is similar to a cup with pleats on the circumferential wall 112. The sheath 11 includes a flat close end that serves as infrared window 111, and an open end for engaging the ring-shaped base 12. When the ring-shaped base 12 is fitted on and engaged with the probe of a tympanic thermometer, the infrared window 111 has to adhere flatly to an opening of the probe. However, pleats may appear on the infrared window 111 of probe cover 10, and stray radiation occurs to influence the precision of the temperature measurement. Additionally, the insertion of the circumferential wall 112 with pleats into the ear scrapes the skin of the ear canal and causes a noise that is similar to something entering the ear and makes patients feel uncomfortable.
FIG. 2 shows another probe cover 20 for tympanic thermometer disclosed in U.S. Pat. No. 5,088,834. The probe cover 20 includes a base 22 connected to a unitary frustum-shaped sheath 21 formed of infrared transparent material. The infrared window 211 at the closed end has the thinnest thickness of between 0.001 and 0.005 inch, while the wall 212 is thicker than the infrared window 212. The base 22 circumferentially engages the open end and is used to secure probe cover 20 on the probe. Although such probe cover 20 does not have a pleat and is more comfortable to patients, it has the drawback of poor uniformity on the infrared window 211. Since the sheath 21 extends by plastically deforming from its proximal open end to its distal closed end, the surface area also changes from a plane to a multiplied frustum-shaped, and the thickness changes from 0.03 to 0.0005 inch. Importantly, the infrared window 211 is not certified to have a uniform plastic conformation.
The present invention provides a probe cover of a tympanic thermometer that permits transmission of infrared and fits the shape of an ear canal. The probe cover comprises a base having a central opening and a sheath formed by thin film. The sheath comprises an infrared window with an approximately uniform thickness for sensing infrared radiation, an open end attached to the base and a circumferential wall extended from the open end to the infrared window. The thickness of the circumferential wall is smaller than that of the infrared window.
The primary objective of the present invention is to provide a probe cover of a tympanic thermometer and tympanic thermometer assembly. The infrared window of the probe cover is not influenced by plastic deformation, so that the uniformity of the thickness is improved to provide a precise measurement of the patient""s temperature.
The second objective of the present invention is to provide a probe cover with low production cost. The probe cover is designed to engage the probe of a tympanic thermometer in a simple manner; it adapts to mass production and the production cost is therefore decreased.
The third objective of the present invention is to provide a probe cover with smooth circumferential wall to cover the probe of a tympanic thermometer. When such a probe cover is fitted on the probe of a tympanic thermometer, and then inserted into an ear canal, the probe of a tympanic thermometer strains the probe cover and the circumferential wall is free of pleats to avoid generation of noise.
To achieve the above-mentioned objectives, a probe cover of a tympanic thermometer is provided. The probe cover comprises a base and a sheath attached on the base. The base is a ring-shaped thin object with a central opening permitting the probe of a tympanic thermometer to pass and engage the flanges on the bottom of the probe. The sheath comprises a circumferential wall that strains and circles around the sidewall of the probe, and an infrared window is fitted on the opening at the front end of the probe. Since the thickness of the infrared window is thicker than that of the circumferential wall and the infrared window is free of pleats to keep a very uniform thickness, infrared radiation can penetrate through the infrared window to the probe of a tympanic thermometer for measuring the body temperature precisely.